This is because immigration from inside the EU cannot be controlled, and neither can a limit be placed on genuine claims for asylum.

Former Labour minister Frank Field, a member of a cross-party group on immigration, welcomed Mr Woolas's comments.

The MP for Birkenhead said when the country was moving into a recession the immigration policy suitable for a boom was unsuitable.

He said the key was to "break the link" between people coming to the UK to work and gaining citizenship, which increased the population.

'Distorted picture'

Sir Andrew Green, chairman of Migrationwatch, which argues for balanced migration, told BBC Five Live Mr Woolas's remarks showed a significant development in the immigration debate.

"This is the very first time that a government minister has recognised the link between immigration and population," he said.

But the chairman of the Commons Home Affairs Select Committee, Keith Vaz, said he disagreed with Mr Woolas.

A Labour government had never supported a quota for immigration, he said, adding that the points-based system was based on needs of the economy and not numbers.

He said the government should avoid providing a vehicle for the "distorted picture the far right will want to portray".

People have looked for scapegoats in immigrant communities for economic problems and in fact exactly the opposite is the case

Chris Huhne, Liberal Democrat home affairs spokesman

Keith Best, chief executive of the Immigration Advisory Service, said immigration quotas were not workable in a modern trading economy.

"What are you going to say to the employer who is desperate to fill a job, but can't find anyone suitable in the European economic area?" he said.

"Are you going to say 'sorry, the quota has been filled, you'll have to wait till next year'?"

Chris Huhne, the Lib Dems' home affairs spokesman, said it was surprising the issue was being considered now, when many immigrants were returning home because of the financial crisis.

"I do find it rather worrying that Labour and the Conservatives seem to be opening up this debate now at a time when traditionally people have looked for scapegoats in immigrant communities for economic problems, and in fact exactly the opposite is the case.

"The people who get the hardest hit first are often migrant communities."

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